wagner



July 17, 1923. 1,461,841

R. WAG N ER SCREW PROPELLER Filed June 15, 1921 2 Sheets-Sheet 1 [11/12 nfar;

7/2 /17 U W g/ 31/ i/wmce July 17, 1923.

R. WAGNER SCREW PROPELLER Filed Jun 15.

1921 2 Shun-Shut 2 FIG. 9.

FIGB.

FIGJO.

fill 67in); Wu d1 Wagner Patented July 17, 1923.

UNITED STATES PATENT OFFICE.

BUDOLF WAGNER, or HAMBURG, GERMANY, ASSIGNOR TO s'riiacon'rnarnorsmm LTD. A./S., or GHRISTIANIA, NORWAY.

SCREW PROPELLEB.

Application filed June 15, 1921. a Serial No. 477,738.

(GRANTED UNDER THE PROVISIONS OF THE ACT OFMARGH 3, 1921, 41 STAT. I, 1313.)

To all whom it may concern: 7

Be it known that I, RUDOLF WAGNER,

. chief engineer, a citizen of the German Revolving propeller,serve for the direction of the revolving propeller stream into an axial flow. In known constructions, the vertical portion of the rudder post, upon which the rudder is mounted, has never been made use of to assist in the production of this directive efiect, but it has been disposed between two laterally situated blades of the counter propeller and exposed to the propeller stream. Not only was this post not utilized, but, in addition, it offered a not inconsiderable resistance to the propeller stream, seeing that there was a somewhat intensive impact of the said stream against the post. This defect Was partly avoided by disposing vertical blades of the counter propeller in front of the side of the post concerned, but the post still stood out or projected beyond the blades in question and offered resistance.

According to my invention, the aforesaid defectsare avoided by shaping the forward edge portion of the rudder post somewhat in the form of a blade of sufiicient width for imparting axial direction to the stream coming from the propeller. The portion so shaped is preferably that portion lying within the circle formed by the tips of the revolving blades as seen from the stern. In this manner an integral combination of the counter propeller with the rudder post is obtained, and the blade shaped portion of the said post may also serve for the attachment of laterally situated blades of a counter propeller. In this Way, the previously proposed extension of two of the auxiliary or counter blades beyond the circle described by the tips of the revolving propeller and outwards to the hull of the ship, for the purpose of securing the counter propeller, is avoided, such extension of the blades was disadvantageous, because parts of these extensions were submerged so that they offered resistance. It is not necessary for the blade-shaped portion of the rudder post to be made in one piece with the rudder post itself, as 1t may be separable from the rudder post proper and so as to make a joint,

. either transversal or longitudinal, for enpart of a ship fitted with a counter propeller and rudder post in accordance with these improvements.

Figure 2 is an end elevation of the construction seen in Figure 1.

Figure 3 is a cross section on the line Al3 of Figure 1.

F igure 4 is a cross section on the CD of Figure 1.

Figure 5 is a rear elevation of a modified construction differing somewhat from that seen in Figure 2.

Figure 6 is a front elevation of the counter propeller and lower portion of the rudder post seen in Figure 5.

Figure 7 is a cross section of another modified construction of blade formation on the rudder post and of a rudder mounted there- Figure 8 is a view similar to Figure 1 of another construction adapted for facilitating the removal of the main, propeller.

Figure 9 is a cross section on the line E-F of Figure 8,

Figure 10 is a cross section on the line G-H of Figure 8,

Figure 11 is a plan section showing another mode of removably mounting the blade like portions on the rudder post proper, and

Figure 12 illustrates a method of mounting a hollow blade-like portion on the rudder post proper.

Referring to Figure 1, 1 is the stern post,

line

.2 is the rudder post, 3 is the counter propeller, 4; is the main propeller, and 5 is the rudder of a single screw propeller ship. In this construction, the rudder post 2 is assumed to be made in one integral piece with the portion 3 which is shaped in the fashion of twoIblades of'a rigidly fixed counter propeller. The distance 6 between the main and counter propellers is of suilicient width toyprevent fouling by foreign bodies getting between. If the propeller is not of the "type comprising a hub with removably mounted blades, the removal of the propellermay be accomplished by withdrawing the propeller shaft a little into the ship, thereby giving sufficient space for the withdrawal of the presence of the hood or cap prevents the winding aroundthenut of rope, or other material that may get between the propellers. v

As will'be seen clearly fron'i Figures 1, E2 and 4' further blades 8 which may be used on the counter propeller may be removably attached to the rudder post portion 3, this removable attachme'nt'of the further blades giving a more favourable shape for the forging orcasting of the rudder post than would be the case were the blades to be made integrally with the said post. The blades 8 may be formed in pairs and each pair may be secured to the centre part 3 by means of bolts 9, or may be riveted thereto. The radial length of the counter propeller blades 3 and 8 has been assumed, in this construction, to be considerably less than that of the main propeller because the reliability of the counter propeller is thereby increased and,

as has been shown by theoretical investigation and practical experience, the outer portions of these blades have a quite inconsiderable useful efiect.

As shown in Figures 1 and 3, it may be advantageous to shape these portions of the post 2 which lie outside of the propeller circle so that they'are reduced forwardly to a cutting edge or are of somewhat streamline cross section, thereby reducing the resistance offered by these parts.

In Figure 4:, the direction of rotation of the propeller 4 is indicated by the arrow 10 and the axially directed motion imparted by the blades of the counter propeller, and particularly of the blade'like portions 3 on the rudder post 2 is indicated by the arrow 11.

In the modification seen in Figures 5 and 6 it is again assumed that the blade-like portions 3 are formed integrally with the post '2, but, in order to simplify the construction there are only two laterally disposed blades 12, so that the counter propeller comprises only four bladesinstead of six as in Figures 1 to l. In this construction, however, the blades 12 are assumed to be formed integrally with the blades 3 and the post 2. To compensate. for the reduced number of blades the latter may be made a little wider than in Figures 1 to 4L, and, it necessary, the blades may be made with an increased twist or curvature attheir outer ends. An advantage of this construction is the reduced cost for its manufacture, and a further advantage, which will be apparent from Figure 6, is the reduced diameter of hub 13 which'is possible with this construction. Investigation has shown that it is important to make the fullest possible use of the core poition of the propeller'streain, and this is rendered possible by the use of a hub of small diameter.

Figure 7 illustrates a construction. in which another source of loss is avoided. Heretofore, in most cases, there was a relatively large space between the rear edge of the rudder post and the leadingedge of the rudder, and in this space the propeller stream, having great intensity, suffered considerable loss by reason of the impact and eddies. According to Figure 7, the rudder post is constructed thicker than usual, which is possible when making it of the blade like construction'aforesaid, and this enables the pivot eyes 14 to be disposed that they do not protrude, being overlappedat the sides to a certain extent by recessed edge portions of the rudder and rudder post, and the forward edge of the rudder to bebrought. up close to the rear edge of the rudder post, so that the stream has a smooth passage past the joint between the rudder post and the rudder. The rudder is seen in its central position and the limits of its deviation to either side of the central position are indicated by the chain lines 15. When the rud der post is of large size it may be made hollow, as shown, for the purpose of reducing its weight.

Referring to Figures 8 to 10, the blade like part 3 is removably attached to the rudder post 2, principally for the purpose derstood from Figures 8 and 10, the removal of the blade likepart 3 gives a space extending from the end of the propeller shaft to the line'16 for the removal of the propeller 4, the line 16 being the transverse joint between the part 3 and the rudder post 2. The detachable 'part 3, fitted with auxiliary blades 8, may, ifrequired, extend over the full height of the propeller cavity and, for the more reliable absorption of the lateral forces or for preventing the turning of the part 3 about the rudder post 2, it may extend over the propeller 4 by means of the curved arm or part 17. The part 17 may be lit) flanged, as seen in Figure 9, and the blade like part 3 may be secured in position partly by means of bolts 18 passed through the flange and the rudder post 2 or the stern post, as the case may be, and partly by means of clamps 19 embracing the rudder post 2, bolts 20 being passed through the part 3 and the jaws of the clamps and set screws or clamping screws 21 or the like serving for fastening the clamps to the rudder post 2. If desired, a foot portion 22 may be bolted to the keel bar 23 of the stern post. In this construction, the removable blade-like part 3 serves also for the stiffening of the rudder post 2. As will be seen from Figure 10, the rear edge of the part 3 is of the same thickness as the forward edge of the post 2 against which it abuts, so that a favourable surface for the guidance of the propeller stream. is afforded.

According to Figure 11 the blade like portion 3 of the rudder post is divided into two parts 3 and 3 in a central perpendicular plane 24 by the hub of the counter propeller and the rear edge portions of these blades 3 and 3 bear against or lap over respective sides of the rudder post 2 in planes parallel with the longitudinal axis of the ship. The rear edge portions have sufficient thickness for providing. for example, a flange for over-lapping the post 2 at the back side of the blades, whereby the front sides may merge into the appropriate surfaces of the post 2. as seen in Figure 11 so that the stream has a smooth passage past these surfaces and no resistance is created. The removable blade parts 3 and 3 may be attached to the post 2 by means of bolts 26.

According to Figure 12, the blade-like portions are made hollow and, conveniently, of sheet metal 27. At their rear edge portions. these blades embrace the post 2, as shown, being attached thereto by bolts 28, or by screws or rivets. If the blades are made each of two plates, the forward edges of such plates may be united by screws, bolts or rivets, or, if desired, by welding. The blades may, however, be made by folding and bending a single sheet of metal, as will be readily understood.

What I claim is 1. An improved propelling means for ships comprising, in combination, a screw propeller, and a rudder post, forward portions of the vertical body of said post being blade shaped whereby to act as guiding apparatus.

2. A propelling means according to claim 1, said rudder post carrying laterally disposed guide blades. v

3. A propelling means according to claim 1, said blade shaped portions being jointed to the post.

1. A propelling means according to claim 2, said blade shaped portions being jointed to the post.

5. A propelling means according to claim and clamp means for connecting the blade shaped portions and the post.

6. A propelling means according to claim 4;, and clamp means for connectingthe blade shaped portions and the post.

In testimony whereof I affix my signature in presence of two witnesses.

RUDOLF WAGNER. lVitnesses:

CI-Inrs'r HAFERMANN, E. KAsrAUK. 

